Telephone system



Filed July '7, 1930 3 Sheets-Sheet Inuenlor "d 5 Fe ersun Edwa Nov. 29,1932. E. s. PETERSON TELEPHONE SYSTEM Filed July 7, 1950 3 Sheets-Sheet2 Tnuen c1r- E dward 5. Fe arson Nov. 29, 1932. E. s. PETERSON TELEPHONESYSTEM Filed July 7, 1950 3 Sheec's-Sheet 5 1 mm Edward 5P2 arson fi /7Z l Nov. 29, 1932 UNITED STATES PATENT OFFICE EDWARD S. PETERSON, OFCHICAGO, ILLINOIS, AS SIGNOR, BY MESNE ASSIGNMENTS, TO

ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHICAGO, ILLINOIS, ACORPORATION OF DELAWARE TELEPHONE SYSTEM Application filed July 7, 1930.Serial No, 465,901.

This invention relates in general to telephone systems and in particularto automatic telephone systems in which connections may be establishedthrough the medium of subscriber controlled step-by-step switches. Moreparticularly the invention is concerned with a system of the abovecharacter which is combined with or has superimposed on it, so to speak,a special signalling or messenger call service system; and the broadobject of the invention may be said to be the provision of new andimproved auxiliary apparatus for use in connection with a telephonesystem.

it is an object to provide a telephone system in which certainsubscribers in addition to being able to establish regular telephonicservice with other subscribers, may, by dialling a special number signala telegraph ot- 'fice, thereby dispensing with the usual messenger callboxes which require separate lines to the telegraph oifice.

A special object is the provision of means whereby all subscribersprovided with the special services may dial the same particular numberand immediately upon hearing a tone, replace the receiver, whereupon theauxiliary equipment operates to permanently record the number of thecalling subscriber at the telegraph office, so that a messenger may bedispatched to the subscriber.

A feature of the invention resides in providing a special boosterbattery connection back over the switch train of the connection,

when a subscriber calls the special number,

in order to initiate the operation of the auxiliary apparatus.

Another feature resides in providing a group of relays individual toeach special 40 subscriber, which operate to control the auxiliaryapparatus in a manner to make a record of the number of the associatedsubscriber at the telegraph office.

The above objects and features, together with others which will beapparent hereinafter. Wlll now be described in detail, refer-- onesbeing had to the accompanying drawings comprising Figs. 1, 2 and 3 whichshow by means of the usual circuit diagrams sufficient of the apparatusemployed in a system embodying'the principles of the invention to enablethe same to be easily understood.

Referring to the drawings, which should be placed with Fig. 2 to theright of Fig. l and Fig. 3 below Fig. 2, the subscribers substations Aand A Fig. 1 are the ordinary automatic substations having the usualtalking, signalling and impulse transmitting instrumentalities. Thelineswitches LS and LS are mechanically of the well known rotary type inwhich the wipers have no normal position and move in a forward directiononly. The selector switch S and the connector switch CN, shown inskeleton form, are mechanically of the well known Strowger verticallyand rotary type in which the bank contacts are arranged in horizontalrows or levels. The group of relays RG is one of a number which areseizable by the selector S when its wipers are raised to a special levelof bank contacts.

Fig. 2 shows two groups of relays, SR1 being individual to substatlon Aand SR6 individual to substation A. These relay groups start theoperation of the auxiliary apparatus and also determine the three-digitnumber or code of the associated substation which is to be transmittedto the telegraph olfice. The cut-ofl? switch CO determines the number oftimes the code is to be sent to the telegraph office and is a rotarystep-by-step switch in which the wipers move only in a forward directioneach time the armature of its magnet retracts its armature.

Fig. 3 illustrates the code sender switch CS which is of the sameconstruction as the cutoil switch CO. This code sender switch togetherwith the associated group of control relays operates to transmit thethree digit code or number of a calling substation, over a trunk lineextending to the telegraph ofice where the punch register PR isoperated.

The system having been described in general a detailed description willnow be given of its operation. For this purpose it will be assumed thatthe subscriber at the substation A desires to establish an ordinarytelephone connection with the subscriber-at substation A. Upon theremoval of the receiver at the substation A a circuit is completed forline relay 15 of the lineswitch LS and over the line conductors 5 and 6.Line relay. 15 upon energizing closes acircuit for the switching relay10 and rotary magnet 25 in series at armature 16, and at armature 17connects the test wiper 19 to a point midway between the switching rela10 and stepping magnet 25. A branch of t e ground circuit from armature16 extends over conductor 14 to the connector bank to maintain the linebusy at this time. A branch of conductor 14 extends to relay 100 of Fig.2, but due to its high resistance it cannot energize at this time. Fromthis point the operation depends upon whether the selector S or otherselectors connected to the bank contacts of the lineswitch LS are busyor idle. If the selector with which wiper 19 is engaged is busy, groundwill be extended over wiper 19, armature 12 and its back contact,armature 17 and its front contact, back contact of armature 26, throughthe windin of the stepping magnet 25, to battery. T e switching relay 10is thereby short-circuited and the stepping magnet 25 is operated in themanner of a buzzer to rotate the wipers 18, 19 and 20 over theirassociated bank contacts. As soon as an idle selector, such as S, isencountered, ground potential will no longer be present on the testwiper 19, and therefore the switching relay 10 is no longershort-circuited and it energizes in series with the stepping magnet 25.However, owing to the high resistance of the switching relay 10, thestepping magnet does not operate in series with it. Switching relay 10upon energizing disconnects the test wiper 19 from its armature 12 andits back contact and connects it directly to the private normalconductor 14.

As a further result of its energization switching relay 10 disconnectsthe circuit of the line relay 15 from its armatures 11 and 13 and thenconnects the line conductors 5 and 6 directly through to the wipers 18and 20, and over conductors 21 and 23, armatures 51 and 54 and theirback contacts to battery and ground through the upper and lower windingof line relay 30 of the selector S. Line relay 30 upon energizing closesa circuit for slow-release relay 35 from its armature 31 to ground atarmature 53. At armature '36 relay 35 upon energizing extends groundover the release trunk conductor 22 to render the selector busy, and atarmature 37 the circuit for series relay 40 and vertical stepping magnet55 is prepared.

The calling subscriber A now operates his calling device S in accordancewith the first digit of the desired number, thereby producing a seriesof interruptions in the circuit of the line relay 30 of the selector S.As soon as the line relay deenergizes in response to the first of theseinterruptions it completes a circuit from ground on armature 53,armature 31 and its back contact, armature 37 and its front contact,through the winding of the series slow-release relay 40 and the windingof the stepping ma net 55, to battery. Slow-releaserelay 40 and thestepping magnet 55 energize in series over this circuit and the verticalmagnet upon operating raises the wipers 61, 62 and 63 of the selectorone step opposite its first level of bank contacts, whereupon theoil-normal springs 58 and 60 immediately operate. As a result of theclosure of the off-normal spring 58 a circuit is completed from groundat release conductor 22, armature 41 and its front cont act, through theofi-normal springs 58, contacts 57. through the winding of the steppingrelay 45, to battery. At armature 46 relay 45 completes a lockingcircuit for itself and at armature 47 prepares a circuit for the rotarymagnet 56. Relay 40 remains energized as also does relay 35 betweenimpulses of a series.

The remaining impulses of the series operate the vertical magnet 55 toraise the wipers opposite the desired level of bank contacts, andshortly after the last impulse slowrelease relay 40 will deenergize andclose a circuit for the rotary magnet 56 and its armature 41. Rotarymagnet 56 upon energizing rotates the wipers 61, 62 and 63 intoengagement with the first set of bank contacts of the level, and at itsarmature 57 o ens thecircuit for the stepping relay 45. tepping relay 45upon deenergizing opens another point in its circuit at armature 46, andat armature 47 opens the circuit of the rotary magnet 56, and thismagnet upon deenergiz ing again closes its armature 57 to prepare a newcircuit for stepping relay 45.

From this point the operation depends upon whether the first trunk lineterminating in the first set of contacts in the bank is busy or idle. Ifit is busy stepping relay 45 energizes again over a circuit extendingfrom ground by way of the test contact with which wiper 62 is inengagement, armature 52 and its back contact, closed off-normal springs58, armature 57 and through the Winding of relay 45, to battery. Thisrelay upon again energizing closes a locking circuit for itself atarmature 46' and at armature 47 again completes a circuit for rotarymagnet 56. This alternate operation of the stepping magnet and therotary magnet continues so long as test wiper 62 engages groundedcontacts.

I will now assume that the trunk line extending to the connector switchON is idle, and that being the case the wipers 61, 62 and 63 of theselector will arrive on bank contacts 67, 68 and 69 as there is nolonger ground potential upon contact 68 the stepping relay 45 no longerenergizes. The switching relay 50 is no longer shunted and it energizesfrom ground on the release trunk conductor 22, through the winding ofswitching relay 50, off-normal contacts 58, armature 57 and in seriesthrough thewinding of the relay 45.

Ill

to battery. The stepping relay 45, however, does not energize in thiscircuit due to the high resistance of switching relay 50. Relay uponenergizing removes ground from armature 53 so that slow-release relay 35will deencrgize, and at armature 52 disconnects the-test wiper 62 fromthe point between the switch'ng relay 50 and stepping magnet 45 andconnects it instead to ground by way of the release trunk conductor 22at armature 36, thus making the trunk line busy immediately, and atarmatures51 and 54 disconnects the trunk conductors 21 and 23 from thewindings of line relay 30 and extends them by way of the front contactsof these armatures, wipers 6'1 and 63, bank contacts 67 and 69, over thetrunk conductors to the line relay of the connector CN. The connectorCNthereupon operates and places ground upon the release trunk conductor 22to establish the usual holding circuit for the selector S and thelineswitch LS before slow-release relay .35 of the selector S has timeto deenergize.

The calling subscriber now operates the calling device S in accordancewith the second digit of the called number. The connector CN is therebyoperated'to raise its wipers to the desired level of bank contacts. Thesubscriber then dials the third or final digit of the called number andas a result the connector rotates its wipers into connection with theline extending to substation A, and in the usual manner upon thecompletion of the connection the called line is signalled tonotifythesubscriberthathe is wanted. When the called party answers theconversation will proceed and when'it is completed the sub scribers willreplace their receivers, bringing about the release of the connection inthe usual manner. As the foregoing operation of the connector switch UNis well understood it is not thought necessary to further describe itsoperation in detail, except to state that upon the release of theconnection the connector switch CN removes the holding ground fromrelease trunk conductor 22, which likewise opens the circuit of theswitching relay 50, so that this relay upon deenergizing will close acircuit from armature 53 through armatures 31 and 37 off-normal springs60 and then through the winding of the release magnet 59, to battery.The release magnet upon energizing restores the wipers of the selectingswitch S to normal. The lineswitch LS is also restored to normal byremoving the ground from the release trunk conductor 22 which held theswitching relay 10 energized and as ground is no longer encountered onthe busy guarding circuit 14 the subscriber at substation A is availablefor any incoming calls.

The foregoing describes an ordinary telephone connection which may beestablished between any two subscribers in the system,

system having the messenger service available or who subscribes for thisservice.

.Upon the removal of the receiver at the substation A the lineswitch' LSoperates, as has been explained, to seize an idle selector switch S andwhen one has been found the subscriber dials a particular number so thatthe wipers of the selector are elevated opposite a particular level ofbank contacts, over one of which a number of relay groups, such as RG,may be reached. When an idle relay group, such as RG, has been seized bythe selector S the wipers 61, 62 and 63 will be positioned upon bankcontacts 64, 65 and 66, and the relay 7 5 will become ener ized frombattery through its upper winding, line conductor 21, line conductors 5and 6, of the substation A, line conductor 23, through the lower windingof relay 75, to ground, through the primary winding of the tone machineT. The subscriber at substation A will hear a tone in his receiver,which is generated by the tone machine T, and thereby become aware ofthe fact that his line has been connected with the auxiliary signallingequipment and that the telegraph office will be signalled for amessenger who will be promptly dispatched to the subscribers premises.If the subscriber after hearing the tone, desires, he may immediatelyreplace his receiver upon the switchhook, thereby automaticallyreleasing the selector switch S and the lineswitch LS to normal, so thatthis equipment will be available for other calls or for another call bythe same subscriber to another subscriber.

Relay 75. of the relay group RG upon energizing, at its armature 7 6 andits front contact closes a locking circuit for itself from ground atalternate front contacts of armature 81 so that this relay will remainenergized in case the subscriber A should immediately replace hisreceiver and release the connection upon hearing the tone from the tonemachine T. As a further result of the energization of the relay 7 5 itattracts its armature 77. This armature, it may be explained, is of atype which has a weight attached to one end of it so-that it willvibrate r'or a certain length of time before coming completely 'to restonto its front contact, whereupon a circuit is completed from groundthrough this armature, through the winding of slow-to-pull-up relay 80,to battery. At armature 78 and its front contact, relay 75 momentarilyconnects the booster battery B to the conductor 90. This booster batteryB, it may be explained, is of slightly higher voltage than the ordinarybatteries indicated on the relays in the drawings and has the effect ofboosting or assisting these batteries. This booster battery is therebyextended momentarily throu h the resistance, the alternate contacts ofarmature 78, conductor 90, bank contact 65 and wiper 62 which is restingupon it, armature 52 and its front Contact, release trunk conductor 22extending through the selector S, wi er 19 of the line switch LS,armature 12 an its front contact, conductor 14, (which is grounded whenthe switches are in use to prevent other calls from coming in on themover conducfor 14) Fig. 2, through the winding of high resistance relay100, to battery. The high resistance relay 100 ordinarily will notenergize from round over the release trunk conductor 14, but as in thisinstance the booster battery B is connected to this conductor this relaywill energize. 7

Referring back to the operation of slowto-energize relay 80, thearmature 82, after armature 78 has been completely attracted anddisconnected the booster battery B from its alternate contacts, willextend ground to release trunk conductor to maintain the relay group RGin a busy condition. At armature 81', relay 80 disconnects the lockingground from relay 75, so that if the subscriber has released theconnection it will become deenergized and at armature 77 upon fallingaway open the circuit of slow-toenergize relay 80 and when this relayretracts its armatures the relay group R will now be in its originalnormal position.

Referring now to Fi 2 it may be stated that the relay group R1 isindividual to the subscriber at substation A while the relay group SR6is individual to the substation A and a relay group, such as SR, istherefore individual to each station in the telephone system which hasavailable the messenger call service. The multiple conductors 128, 129,130, 131 and 132 extending to the top of this figure connect to similarrelay groups in the same manner as the relay groups SR1 and SR6, and thepurpose of these relay groups it may be stated is to set up a numberwhich is individual to its associated substation on the banks of thecode sender OS, Fig. 3. Another purpose is to prevent the operation ofthe code sender CS by any other relay group, such as SR6, while the codenumber of one substation is being transmitted to the telegraph oflice.In other words the equipment temporarily stores up the code number ofits associated substation until the code sender and its auxiliaryequipment is available.

Returning now to the operation of the high resistance relay of thestation relay group SR1, it will be recalled that this relay wasenergized momentarily froin the booster battery B extending over acircuit from the relay group RG, through the selectorS and thelineswitch LS and over the conductor 14.

At grounded'front contact of armature 101,

relay 100 completes a circuit through the winding of relay to battery,and this re- Iayupon energizing closes a locking circuit for itselfextending from ground on back contact and armature 113, front contactand armature 108, through the winding of the relay to battery, so thatthis relay remains locked up even though the high resistance relay 100is deenergized, due to the hanging up of the receiver at the subscribersstation A. At front contact and armature 107, relay 105 prepares acircuit for relay and at armature 106 and its back contact it opens achain circuit extendin in series through all of the station relay Rgroups, so as to prevent any other station from operatin the code senderequipment while the code 0 the instant station is being transmitted. Atfront contact and armature 106 a circuit is prepared for relay 115,extending from battery through the resistance at armature 141 and itsback contact, conductor 130, upper winding of relay 115, armature 111and its back contact, front contact and armature 106, conductor 132, toground at back contact and armature 157. Relay 115 accordingly energizesover this circuit and completes a locking circuit for itself through itslower winding, extending from ground on back contact and armature 113,armature 117 and its front contact, lower winding of relay 115,conductor 131, through the winding of relay 140, to battery. At itsarmature 116 relay 115 prepares a circuit for relay 110, while at itsarmatures 118, 119 and 120 and their associated front contacts theparticular or special code number 384 assigned to substation A is set upon the bank contacts of the code sender OS, by way of the conductor 128.

At the time relay energized it completed an obvious circuit at frontcontact and armature 141 for relay 145, and this relay upon energizingcloses ground from its front contact and armature 146 over conductor142.

through the winding of relay 225, to battery,

Fig. 3.

Before proceeding further with a detailed description of the apparatusand code sender of Fig. 3 it may be stated that this switch ismechanically of the same construction as the cut-off switch CO, in thatthe stepping magnet 240 rotates the wipers 250, 251, 252 and 253 in aforward direction step-by-step over their associated bank contacts. Thearrangement of the bank contacts and the wipers is such that a pair ofwipers, such as wipers 252 and 253, simulate a 50 point switch and inorder to reduce the cost a standard 25 point bank has been provided ineach case, and the operation is such that imfirst half of the bankcontacts overwhic'lr wiper 253 rotates is arranged to pick-up the firstdigit of the codenumber, while the last half of this bank will pick-upthe seconddigit of the code number. Similarly wiper 252 will engage aparticular bank contact in the first half of its bank to pick-up thethird and final digit of the code number. In actual practice the codedigit conductors extending from the bank contacts over which wipers 252and 253 rotate would be connected to an intermediate distributing frame,so that the code conductors extending from the station relay group, suchas SR, could be cross connected for any desired number. In this manneradditional stations may be added or existing ones changed as desired. Inaccordance with the above for the purpose of illustration the stationrelay group SR1 is arranged to set up the code digit number 384 on thebank contacts of the code sender. Conductor 121 therefore extending todigit number 3 on the first half of the bank over which wiper 253rotates, conductor 122 ex tending to code digit conductor 8 in the lasthalf of the bank, while conductor 123 extends to number 4 code-digitconductor in the first of the banks over which wiper'252 rotates. In asimilar manner the station relay group SR6, which is individual tosubstation A is arranged to set up the code number 965 on the banks ofthe code sender.

Returning now to the operation of relay 225 of Fig. 3 at the time it wasoperated from ground on armature 146 of relay 145, this relay uponoperating prepares a circuit for slow-release relay 230 at armature 228,at

armature 229 it prepares a shunting circuit for relay 220, while atarmature 219 it pre pares a circuit for starting the code sender switchCS extending over armatures 226 and 227 as will now be pointed out;ground on armature 219 and its front contact, armature 226 and its frontcontact, wiper 253 and bank contact 259 upon which it is normallyresting, armature 227 and its front contact, through the winding ofrelay 220 and the non-inductive resistance, to battery. Relay 220 uponenergizing closes a locking circuit for itself over its front contactand armature 221 to ground at armature 219, while at armature 222 itprepares a circuit for operating the printing recorder PR at thetelegraph office over conductors 223 and 224. A branch of the circuitextending from ground at armature 219 and its front contact, likewise,extends to armature 216 and its back contact, through the winding ofslow-to-energize relay 210, to battery. The battery through theresistance extending to the other side of the windingofthis relay is forthe purpose of making this relay a. slight amount slower to pull-up,because part of the currentis shunted through the resistance and alsofor preventing excessive sparking at armature 216.

After an interval the relay 210 closes its armature 211 onto its frontcontact and completes the circuit for slow-to-energize rela 205.

elay 205 upon operating closes its armture 206 onto its front contactand completes a circuit extending from ground at armature 219 and itsfront contact, armature 206 and its front contact, armature 231 and itsback contact, back contact and armature 232,

through the winding of relay 215, to battery.

Relay 215 upon energizing opens the circuit of slow-to-pull-up relay 210at back contact and armature 216. Relay 210, after an intervaldeenergizes and opens the circuit for slow-to-pull-up relay 205 atarmature 211, and after a slight interval relay 205 retracts itsarmature 206, so that the circuit for relay 215 is interrupted. Relay215 upon falling away again completes a circuit for slow-topull-up relay210 and the cycle of operation is again repeated, as long as armatures231 and 232 remain at normal. Each time that relay 215 energizes itcompletes a circuit over the trunk conductors 223 and 224 to theprinting recorder PR at the telegraph ofiice,

from ground on armature 219 and its front I ing recording relay PT, backover trunk con-' ductor 224, to battery at the exchange. Each time theprinting recording magnet PR energizes it operates'its armature to printa dot or make a perforation in the moving tape. Each perforationcorresponds to an impulse and a series of these perforations willcorrespond to a particular number or digit of the code. The operation ofthis printing recorder is. well known in the art and it is not thoughtnecessary to further describe its operation.

- A branch of the original energizing circuit of relay 215 extends byway of the back contacts of armatures .231 and 232, through the windingof the stepping magnet 240, to battery, so that each time 'the relay 215is energized the stepping magnet 240 likewise receives an impulse ofcurrent. Accordingly,

step onto their second bank contact. The

' secondbank contactupon which wiper 251 is now resting is grounded butthis has no 'effeet at this time because relay 225 is energized andmaintains armature 228 away from its back contact. As the wiper 253 isnow resting on its second bank contact the conductor #1 connected tothis bank contact has no potential connected to it at this time and noaction takes place. Accordingly, the ste ping magnet 240 continues to--rotate t e wipers step-b'y-step under control of the repeated slowoperations of the relays 205, 210 and 215, until wiper 253 reaches thefourth bank contact connected to #3 conductor or conductor 121 whichrepresents the first'digit of the code number of the operated substationA. During this interval as the wipers are rotated one step at a timeacross the bank contacts, relay 215 operates in 'synchronism and sendsan impulse of current over the trunk line to the telegraph office tooperate the printing recorder three times.

When wiper 253 reaches the bank contact to which the #3 conductor orconductor 121 is connected, a circuit is completed extending from groundat armature 219 and its front contact, armature 226 and its frontcontact wiper 253, fourth'bank contact to which conductor #3 isconnected over first digit code conductor 121, front contact andarmature 120, back over conductor 128, front contact and armature228,thr0ugh the winding of slow-to-release relay 230, to battery. Relay230 after an interval energizes and at armatures 231 and 232 disconnectsthe stepping magnet 240 from under control of the slowoperating relays205, 210 and 215, and over front contacts and armatures 233 and 234 comletes a locking circuit for itself indepen ent of its originalenergizing circuit, from ground at the bank contact upon which wi er 251is now resting. A branch of the loc ing circuit for relay 230 extendsfrom the ground at bank contacts of wiper 251, through armatures 233 and234 to the back contact of armature 241 and the winding of steppingmagnet 240, to battery. Each time the stepping magnet 240 is energizedit interru t-s its own circuit at its armature 241, there y operating'inthe manner of a buzzer to rotate the wipers of the code sender. As afurther result of the energization of slowrelease relay 230 it completesa shunting circuit extendlng around one side of relay 220, from groundedfront contact and armature 235, armature 229 and its front contact,through one sideof the winding of relay 220, thereby shunting out thisrelay, which upon. falling away opens the circuit at its armature 222extending to the printing recorder PR at the telegraph oflice and atarmature 221 it opens its locking circuit.

With relay 230 energized the stepping magnet 240 continues to operate inthe manner same time wiper 251 has reached bank con- I tact 255 which isconnected to the conductor extending to back contact of armature 219 ofrelay 225 which is still energized'at this time. Consequently,slow-release relay 230 and the stepping magnet 240 are no longerenergized as they were over the grounded bank contacts over. which wiper251 has been rotated. After a short interval when relay 230 iscompletely deenergized it again closes the slow stepping circu1t for thestepping magnet 240, at armatures 231 and 232, to place it undercontrol-of the slow-operating relays 205, 210 and 215. At grounded frontcontact and armature 235 the shunting circuit for relay 220 is openedand this relay is again energized from battery through its winding,front contact and armature 227, bank contact 260 upon which wiper 253 isnow resting, front contact and armature 226, to ground at armature 219and its front contact. At armature 221 the locking circuit for relay 220is completed when it energizes, and at armature 222 the circuit for theprinting recording magnet PR is again closed each time relay 215energizes. Accordingly, the second digit of the code number is nowtransmitted to the telegraph office.

The stepping magnet 240 continues to rotate the wipers 250 to 252,inclusive, over their associated bank contacts under control of theinter-action of relays 205, 210 and 215 until wiper 253 encounters thebank contact to which conductor #8 is connected. When this occurs thecircuit for slow-release relay 230 is again completed over a circuitextendin from battery through the winding of thls relay, armature 228and its front contact, conductor 128, armature 119 and its frontcontact, conductor 122, conductor #8 upon which wiper 253 is nowresting, front contact and armature226, to ground on armature 219 andits front contact. Relay 230 after an interval energizes and atarmatures 231 and 232 and their back contacts removes the control of thestepping magnet 240from the inter-action of relays 205, 210 and 215. Atfront contact and armatures 233 and 234 relay 230 completes the lockingcircuit for itself by way of wiper 251 and the grounded bank contactupon which it is now resting. At grounded front contact and armature 235relay 220 is again shunted so as to discon nect the trunk line extendingto the telegraph office and prevent the transmission of furtherimpulses. A branch of the locking circuit of relay 230 again extendsthrough the winding of the stepping magnet 240, to battery, and thestepping magnet thereby is energized and deenergized each time wiper .Itmay be stated at thistime that relay 230 has been made slow-to-releasefor the purpose of preventing it from deenergizingv as the wiper 251steps between the grounded bank contacts.

The wipers 250 to 253, inclusive, of the code sender OS aretherebyrapidly rotated over their bank contacts until wiper 251 reachesits last bank contact 256, and as there is no ground potential uponthisbank contact the slow-release relay 230 is no longer maintainedenergized and, likewise, the stepping magnet 240 has its circuitinterrupted. At

armaturcs 231 and 232 relay 230 upon falling away places the step ingmagnet 240 again under control of the inter-acting slow relay s 205, 210and 215, and at armatures' 233 and 234 a further point in the circuitofthisrelay and the stepping magnet is opened, at armature 235 the shuntcircuit around relay 220 is disconnected and the relay 220 becomesenergized immediately upon'the wiper 252 being stepped onto its bankcontact 258. The circuit for relay 220 now extends from battery throughthe resistance, the winding of the relay, front contact and armature227, back contact258, wiper 252 which is now resting on this bankcontact, front contact and armature 226, to ground on front. contact andarmature 219. At armature 221 the locking circuit for relay 220 is againcompleted, while at armature 222 the circuit extending to the telegraphoffice printer is coin- .pleted when relay 215 energizes. The'steppingmagnet 240 continues to advance the wipers of the code sender CS undercontrol of inter-acting relays 250, 210 and 215.

At this time it will be noted that whereas the wipers 250 and 252 willbe rotating over the bank contacts, the other wipers 251 and 253 will berotating in an arc'away from vthe bank contacts, so that they will notbe effective. The printing recorder PR at the telegraph office isoperated once each time the stepping magnet 240 advances its wipers onestep, and this action continues until wiper 252 encounters the fifthbank contact to which conductor #4 is connected, whereupon, the circuitfor slow-release relay 230 is again completed over conductor 128, ar-

mature 118 and its front contact, conductor 123, and the wiper 252 andthe bank contact upon which it is now resting. Relay 230 again placesthe stepping magnet 240 under control of the series of grounded bankcontacts over which wiper 250 is now rotating and it also completes itsown locking circuit at armature 233, while at armature 235 it againshunts relay 220 so that further im pulses will not be sent to thetelegraph oflice. At armatures 231 and 232 the inter-action relays aredisconnected from control of the stepping magnet 240 which operates in abuzzer-like action and continues to advance the wipers of the codesender until wiper 250 encounters bank contact 254,. and as this bankcontact is no longer grounded the relay 230 and the stepping magnet 240will no longer be energized. Relay 230 upon falling away slowly,replaces the control of the stepping magnet back again to relays 205,210 and 215 and their inter-action operation.

The shunt circuit forrelay 220 is removed at armature 235 and it againbecomes energized and locks up in order to prepare the trans-- missionof further impulses to the telegraph vided so that the code may be sentany numu ber of times.

The operation of'the code" cut-off switch CO will now be pointed out indetail. As soon as the wiper 252 of the code switch CS,

engages bank contact 257 it completes a circuit extending from groundedarmature 219 and its front contact, armature 226 and its front contact,wiper 252 and bank contact 257 upon which it is now restin conductor143, through the winding of t e stepping magnet 160 to battery,,of thecut-off switch CO. As soon as wiper 252 steps off of bank contact'257the circuit for stepping magnet 160 is opened and consequently, itretracts its armature and advances the wipers 162 and 163 forward onestep onto their first set of bank contacts. -As soon as wipers 250 and252 step off of their last bank contact wipers 251 and 253 will engagetheir first ban-k contacts, the wiper 253 coming to rest upon bank 11%contact 259. The code sender switch CS is now again in the same positionit was at the time that its operation was initiated.

In the same manner as has been heretofore pointed out the code number384 is again transmitted over the trunk line extending to the telegraphofiice to operate the printing recorder PR and again print the number ofthe code of the substation A. In a similar manner all of the relays forcontrolling the code switch CS are operated, as has been pointed out.After the code number has been transmitted the second time the wiper 252again engages its bank contact 257, so that the stepping magnet 160 ofthe cut-off switch CO is energized the second time to rotate the wipers162 and 163 onto their second bank contacts.

Referring again to the cut-off switch CO it will be noted that the wiper162 requires three or four times. Each time the wipers of the codesender CS make one complete revolution over their bank contacts intransmitting a complete code number, the .cut-ofl switch G0 has itsstepping magnet 160 energized once so that for each operation of thecode sender the cut-off switch CO will operate one step. 7

With the wiper 162 of the cut-off switch CO resting on its bank contact164 a circult is completed from ground over the wiper and the bankcontact, through the winding of relay-155, to battery. At armature 156it prepares a locking circuit for itself and at armature 157 and itsfront contact it extends ground from this armature through the resistance 153, winding of slow-release relay 150, multiply connected bankcontacts upon the fourth. one of which wiper 163 is now resting, backcontact and armature 161, and

through the winding of the stepping magnet 160, to battery. Due to theinclusion of the resistance 153 in this circuit the stepping magnet 160does not energize. However, the slow-release relay 150 energizes and atits armature and front contact 152 it short-circuits the resistance 153.At its grounded front contact and armature 151 relay 150 completes thelocking circuit for relay 155 so that it will remain held up after wiper162 is stepped off of bank contact 164. Stepping magnet 160 is nowoperated in a circuit including only the relay 150 and not theresistance 153 and it operates in the manner of a buzzer by interruptingits own circuit at its armature 161. It continues to rotate the wipers161 and 163 in a forward direction over the multiply. connected bankcontacts until bank contact 165 is reached, whereupon the circuit forthe stepping magnet 160 and slow-release relay 150 is permanently openedand the switch is now in its normal position.

As a further result of the energization of relay 155 it connects groundfrom its front contact and armature 158, over conductor 129,-

armature 116 and its front contact, through the winding of relay 110, tobattery. Relay 110 upon energizing closes a locking circuit for itselffrom armature 107 over its armature 112, and at armature 111 and itsback contact opens a point in the chain circuit 132 extending betweenthe station relay groups SR. At armature 113 and its back contact relay110 opens the locki circuit .1501 relay 105 extending over armat e 108and this redigit conductors 121, 122 and 123 is disconnected. Relay 105which was released due to the opening of its locking circuit at armature113 restores the chain circuit over con-' du'ctor 132 and its armature106 so that any other station relay group, such as SR6, which may have acode stored in the group of relays may seize the code sender OS tooperate it and tignsmit the associated code to the telegraph o co.

As a further result of the release of relay 110 and the opening of itsarmature 113 from its back contact, relay 140 is restored to normal andat its armature 141 and back contact again restores the battery to themultiple conductor 130 so that-any other relays, such as 115, or otherstation relay groups may seize the code sender equipment. Relay 140 uponreleasing opens the circuit of relay 145 at its armature 141, and relay145 upon releasing in turn opens its armature 146 from grounded frontcontact, thereby interrupting the circuit for relay 225 which extendedover conductor 142. Relay 225 upon restoring opens the armature 219 fromits front contact thereby disconnecting the ground circuit from the slowinter-acting relays 205, 210 and controlling relay 215. At armature 227the initial energizing circuit of relay 220 is opened, while at armature228 the energizing circuit for relay 230 is likewise interrupted. Thecode sender switch wipers are now in their normal position as are alsothe group of relays which control them. The cut-ofi switch G0 haslikewise been restored to normal as well as all of the relays whichcontrol it and also the station relay roup SR1.

The code sender C is now in position to transmit another code which maybe sent in by any other subscriber. The code number 384 which isindividual to the substation A has been printed four times upon the tapeat the telegraph oflice by the printing recording relay PR and anattendant at the telegraph oflice upon noting the code number willdispatch a messenger to the premises of the subscriber, who may receivea telegram message which is to be transmitted from the telegraph officeor perform some other messenger duty.

From the foregoing detailed description of the operation it will beappreciated that only one code at a time may be transmitted by the codesender CS to the telegraph ofiice, but should more than one subscriberin the system dial the number to seize its associated relay group, suchas RG, the equipment will operate to engage with the associated stationrelay group SR and store the code in the group of relays, andimmediately upon the transmission of this code the next precedingfice'the code would be mutilated or an incor-- rect code would betransmitted. In order to take care of this the code sender switch CS isarrange-d to automatically restore its wipers to their normal positionswhenever they are accidently stepped off of the first step of the bankcontact which is their normal position. When this occurs and wiper 251is moved onto its second bank contact, ground is extended from this bankcontact over the wiper, back contact and armature 228, through thewinding of slow-release. relay 230, to battery. Relay 230 uponenergizing completes a locking circuit for itself at armature 233 inseries with armature 234. A branch of the holding circuit'of relay 230extends by way of armature 241, through the winding of thestepping-magnet 240, to battery. The stepping magnet 240, therefore,operates, in the manner of a buzzer by interrupting its own circuit atits armature 241 and rapidly rotates the wipers 250 to 253, 1nclusive,of the code sender CS in a forward direction over their associated bankcontacts. When wiper 251 reaches bank contact 225-instead of picking updirect ground from the associated bank contact it completes a circuitthrough the conductor extending to the back contact and armature 219 andground, and the rotary action continues.- Upon wiper 251 stepping oil ofbank contact 256 wiper 250 will engage the first bank contact which isgrounded and the stepping magnet 240 continues to be alternatelyenergized and deenergized, stepping the wiper 250 and the other wipersacross their bank contacts until wiper 250 steps ofl of the last bankcontact in the arc, in which position the code sending switch GS is atnormal, whereupon the circuit for the stepping magnet 240 and likewisethe slow-release relay 230 is interrupted and relay 230 upon restoringits armature opens a further point in the circuit of the stepping magnet 240. The switch has now reached its normal position ready to receivea code numcode slgnalling equipment to transmlt a code her and transmitit to the telegraph oifice.

As the example illustrated and described comprises only a three digitsystem it will be appreciated that this may be changed to a large one bymerely including additional selectors such as S, or it may be reduced ifdesired. Similarly the code signalling equipvment may be arranged totransmit more or less than the number of digits indicated. For thesereasons it is not desired to limit the invention to the exact embodimentas has been described, but only to the extent of the appended claims,

What is claimed is:

1. In a combined telephone and signalling system, a central exchange,subscribers lines connected to said exchange, means atsaid exchan econtrolled by a calling subscriberfor esta lishing a telephoneconnection with any other subscribers line, code signalling equipment atsaid exchange, code relays at the exchange individual to eachsubscribers line, means controlled by a calling subscriber for operatingthe associated code relays to start the operation of said signallingequipment, a recording ofiice connected to said exchange, and meanscontrolled by said signalling equipment to transmit a codecharacteristic of said callin subscriber over the connection to saidrecor ing ofiice.

2. In a combined telephone and signalling system, a central exchangehaving automatic switches over which telephone connections areestablished between subscribers lines under control of acallingsubscriber, code signalling equipment at said exchange, means controlledby a calling subscriber for establishing a connection over saidautomatic switches with said signalling equipment, means individual toeach of said subscribers lines for controlling said signalling equipmentto generate a code characteristic of said calling subscriber, atelegraph ofiice connected to said signalling equipment, and meanscontrolled by said signalling equipment for transmitting said code aplurality of times to said telegraph oflice.

3. In a combined telephone and signalling system, subscribers linesextending to an exchange having automatic switches over which thesubscribers control the establishment of telephone connections, codesignalling equipment at said exchange, codegenerating means individualto each subscribers line, booster battery means accessible to saidautomatic switches, means controlled over any subscribers line forestablishing a signalling connection over said switches with saidbooster battery means, means responsive to said connection for extendingsaid booster battery means back over said automatic switches to operatesaid code generating means individual to the calling line, and meansresponsive to the operation of said code generating means forcontrolling said characteristic of said calling line.

4. In a combined telephone and signalling system, an exchange havingautomatic switches controlled by calling subscribers for establishingtelephonic connections with called subscribers, code signallingequipment in said exchange, code generating means individual to eachsubscribers line, booster .battery means accessible to said subscriberslines, means controlled by a calling subscriber for controlling saidautomatic switches to establish a connection with said in line aplurality of times to said telegraph o ce.

5. In a combined telephone and signalling system, an exchange havingautomatic switches over which subscribers control the establishment oftelephone connections, a holding relay accessible'to said automatlcswitches, a relay group "individual to each subscriber for initiating acode characteristic of said subscriber, code signalling equipmentcontrolled by said individual relay groups, means responsive to the samecontrol of said switches by any of saidsubscrlbers for operating saidholding relay, and means responsive to theoperation of said holdingrelay to control said relay group and. operate said code signallingequipment only in accordance with the code of the calling subscriber. A

6. In a signalling system, a'plurality of lines each identified by acertain code des gnation, a plurality of control means, a series ofselecting switches controlled by a hne to select an idle one of saidcontrol means, code registering equipment, means responsive to theselection of one of said control means by a line for operating saidregistering equip ment over said selecting switches to register the codedesignation of the line, and means for preventing the registration ofthe code of any other line while the code of the first line is beingregistered by said registering equipment.

7. In a combined telephone and signalling system, a central oifice, aplurality of telephone stations each connected to said central oflice,automatic switches at said ofiiee, means controlled from any telephonestation for operating said automatic switches to establish a telephonicconnection with any other telephone station, relay means accessible tosaid switches, a relay group individual to each of said telephonestations for generating a code designation characteristic of thestation, a signal transmitter at said central ofiice controlled by saidrelay groups, means controlled from any telephone station for operatingsaid automatic switches to select said relay means and operate the same,means responsive to the operation of said relay means for operating therelay group individual to the telephone station over a circuitconnection extending back over said automatic switches, and meansresponsive to the operation of said individual relay group for operatingsaid signal transmitter to transmit a code designation characteristic ofthe telephone station.

8. In'a combined telephone and signalling system, a central oflice, aplurality of telephone stations each connected to said ofiice,

automatic switches in said office, relay means at said oflice, meanscontrolled from any of said telephone stations for operating saidautomatic switches toestablish a telephonic connectionwith any othertelephone'station or a signal connection with said relay means, a relaygroup individual to each of said telephone stations 'for generating acode characteristic of the associated station, signal transmitting meansat said central oflice, means responsive to the connection of saidtelephone station with said relay means for operating the same to givean indication to said telephone station of such connection and forat thesame time operating the relay group individual to the telephone station,and means responsive to the operation of said relay group for operatingsaid signal transmitting means to transmit a signal characteristic ofsaid telephone station.

9. In a telephone and signalling system, a central oflice, telephonesubstations each connected to said oflice, automatic switches in saidoffice, means controlled from any of said substations for operating saidautomatic switches to connect with any other of said substations, signalinitiating means common to said substations, code generating meansindividual to each of said substations for generating a code designationcharacteristic of the associated substation, signal transmission meansconnected to said code generating means, means controlled in the samemanner from any of said stations for operating said automatic switchesto connect with said common signal initiating means to operate the same,means responsive to the operation of said signal initiating means foroperating said code generating means over a connection extending backover said automatic switches, and means responsive to the operation ofsaid code generating means for controlling ,said signal transmissionmeans to transmit the code designation of the calling telephonesubstation.

10. In a telephone and signalling system. a central oflice, telephonesubstations each connected to said office, automatic switches in saidofiice, means controlled from any of said substations for operating saidautomatic switches to connect with any other of said substations, signalinitiating means common to said substations, code generating meansindividual to each of said substations for generating a code designationcharacteristic of the associated substation, signal transmission meansconnected to said code generating means, means controlled from any ofsaid stations for operating said automatic switches to connect with saidcommon signal initiating to the operation of said signal initiating mentin said exchange, means control means for operating said code generatingmeans, and means responsive to the operatlon of said code generatingmeans for controlling said signal transmisslonmeans to transmit the codedesignation ofthe calling telephone substation. v

11. In a telephone and signalling system, a central oflice, apluralityof telephone substations connected to said ofiice, automaticswitches in said oifice, means controlled-from any-of said-substationsfor operating said automatic switches to establish a telephoneconnection with any other of said substatlons,

signal initiating means common tosaid substations, signallin equipmentin said ofiice for transmitting signals of a calling substation, meanscontrolled in a similar manner by any of said substations for operatingsaid automatic switches to establish a connection with said signalinitiating means to operate the same, means responsive to the operationof said signal initiating means for operating said signallin equipmentover a connection extending bac over said automatic switches, and meansresponsive to the operation of said signalling equipment fortransmitting a code designation characteristic of the callingsubstation.

,12. In acombined telephone and signalling system, a central exchangehaving substaion lines extending thereto and terminating in automaticswitches, code signalling e uiped rom any substation for operating theautomatic switches to establish a telephone connection with any othersubstation or for'connecting with said code equipment, means in saidcode equipment responsive to the connection of a substation linetherewith for generating a code indicative of the substation, and means1 for transmitting said code 'over a different connection from saidexchange.

13. In a combined signalling and telephone system, a central exchangehaving substation lines extending thereto and terminating in automaticswitches, code signalling equipment in said exchange, means controlledfrom any substation in accordance with the number of any other desiredsubstation for operating the automatic switches to establish a telephoneconnection therewith, means controlled from any substation in accordancewith a number common to all of said substations for establishing aconnection over said automatic switches with said signalling equipment,means in said equipment respon sive to the connection of any substationtherewith for generating a code individual to only said substation, andmeans for transmitting said individual code from said exchange.

14. In a combined telephone and signalling system, a central exchangehaving substation lines extending thereto and terminating ;ment in saidcentral exchange, means controlled at a calling substation for operatingthe automatic switches in accordance with the number of a calledsubstation to establish a telephonic connection therewith, said meansoperative to control the automatic switches in accordance withanumbercommon to all of said substations to establish a connection with saidsignalling equipment, means in said signallin equi' ment responsive tothe connection 0 a su station therewith for generating a code numberindividual only to that substation, and means operative to transmit saidcode number from said exchange regardless of whether the callingsubstation has been released from its connection with the signallingequipment, v 15. In a combined telephone and signalling system, acentralexchange having substations connected thereto, code signalling equipmentin said exchange, means in said exchange controlled by a callingsubstation for establishing a telephonic connection with any desiredcalled substation, said means controlled in the same manner by anycalling substation for establishing a connection with said signalling'equipment, means for indicating to the substation when such signallingconnection is established whereby the connection may be rel-easedimmediately, means in said signalling equipment for generating a codecorresponding to the calling substation upon the connection therewith,and means for then transmitting said code independently of the continuedconnection of the calling substation with said equipment.

16. In a telephone system in which a signalling'systein is incorporated,a central exchange, substations connected to said exchangeand eachhaving an impulse sender thereat, code signalling equipment at saidexchange, means responsive to the operation of the impulse sender at acalling substation in accordance with the designation of a calledsubstation for establishing a telephone connection therewith, meansresponsive to the operation of the impulse sender at a calling stationin accordance with a designation common to all of said substations forestablishing a connection with said signalling equipment, means in saidsignalling equipment responsive to the connection of a substationtherewith for generating a code individual only to that substation,means for indicating to the connected-substation that the connectionwith the signalling equipment is established so that the connection maybe released if desired, and means in said signalling equipment fortransmitting the code of the calling substation from said centralexchange.

17 In the combination of a telephone system and a signalling system, acentral exchange, substation lines extending to said in automaticswitches, code signalling equip-- exchange, a series of automaticswitches in said exchange controllable by said substation to establishtelephone connections between them, code signalling equipment in saidexchange, means for controlling the automatic switches in the samemanner by all of the substations for establishing a connection with saidsignalling equipment, a circuit connection extendin from the connectedsubstation line to said 0 ment exclusive of said automatic switches, andmeans in said signalling equipment controlled over said circuitconnection for initiating the generation ofa code individual only to theconnected substation.

18. In the combination of a telephone system and a signalling system, acentral exchange, substation lines terminating in said exchan e,automatic switches controlled by any cal ing substation for establishinga telephone connection with any called substation, code signallingequipment in said exchange, a circuit connection extendin from theterminating end of each substatlon line to said signalling equipment,means for controlling the automatic switches in the same manner by anycalling substationto extend a connection to said signalling equipment,means responsive to said connection for energizing said circuitconnect-ion from the terminating end of the substation to initiate theeneration of a code by said signalling equipment which is individualonly to the connected substation, and means in said signalling equipmentfor transmitting said code.

In witness whereof, I hereunto subscribe my name this 2d day of July, A.D. 1930.

EDWARD S. PETERSON.

ode signalling equip-

